Grinding head



Feb. '21, 1928. 1,659,684

C. H. FIELD GRINDING HEAD Filed Jan. 5, 1927 2 Sheets-Sheet 1 IN VEN TOR.

A TTORNEYS.

Feb. 21, 1928. r 1,659,684

c. H. FIELD GRINDING HEAD Filed Jan. 5, 1927 2 sheets-sheet. Z

ATTORNEYS.

Patented Feb. 21, 1928.

PATENT OFFICE.

CHARLES 11 FIELD, or rnov nnncn, nnonn rsmmn.

Application filed January 5, 19 27. Serial No. 159,130.

' This invention relates to an improved construction of grinding head; and has for its object to provide a head-plate over which a sheet of abrasive material is tightly drawn 7 byforcing a ring over the edge thereof to bind the edge ofthe material onto the periphery of t e head-plate. I

A further object of the invention is the provision of means in the head-plate for receiving the folds of the surplus portion of they edge of the abrasive sheet as it is turned back overthe edge of the headplate. l y y With these andother objects in view,'the invention consists of certain novel features I of construction, as will be more fully described, and particularly pointed outin the ap ended claims.

n the accompanying drawin sf V a Figure 1 shows agroup of e elnents comprising the head-plate with a scalloped edge, beneath it a disc or sheet of abrasive material, beneath that the binding ring and beneath the Whole is the tool for forcing the ring and sheet onto the head-plate.

Figure 2 shows the ring and disc positioned in the tool and the head-plate in position to be pressed downwardly to apply the sheet and ring thereto.

Figure 3 shows the head-plate as having been forceddownwardly into the tool whereby the ring and sheet of abrasive material is forced thereonto.

Figure 4 shows the head'plate with the ring and abrasive sheet in position thereon.

Fi ure 5 is a perspective view showing ahe isc-shaped sheet of abrasive material at. a F

Figure 6 shows the sheet of abrasive material as having been drawn up into dish form. V

Figure 7 is an enlarged view showing a fragmental portionof one edge of the headplate Withthe ring forced into position thereon and as binding the abrasive sheet onto the edge of the head-plate. y

Figure 8 is a sectional view showing the scalloped edge on the head-plate and the abrasive sheet with its foldsengaging the recesses of the scalloped edge.

Figure 9 is a view partly in section showing the tool as reversed side for side and a as resting on the tool inp0Slt10I1t Ob riven off of the head-plate the binding rin to releasethe abrasive sheet when *it isdesired to positiona fresh sheet thereon. It is found in the practical construction and operation of grinding heads of this character, in orderto fold .or draw theedges of a sheet of abrasive material over the pe ripheral edge of the head-plate, necessary to providesome space or spaces in the edge of the head-plate for the rece tion of the surplus or folds of the stock 0 thet-urned-back edge of the abrasive sheet so that the parts of the surplus edge will not overlap each other, which overlapping would prevent the binding ring from being forced thereover in a practical Way. Therefore, to accomplish thisin a simple and effective way, I have scalloped the flangeor edge of the headplate to receive the folds of the turned-back portion ofthe abrasivesheet when the rin is forced thereover. Also, I have provided a simple and effective tool for the assembling of the parts whereby it' is only necessary to position the ring in the tool and the abrasive disc-shaped sheet over the ring to receivesuch surplus stock. Also, by the use of such improved applying tool, this tool may be reversed side for side and by placing the head-plate with its ring onto the tool; the ring will readily be driven from its binding position to release the abrasive sheet which is thenreadily removed and a fresh sheet of abrasive material positioned A thereon; and the following is a detailed description of the present embodiment of my invention showing one means by which these advantageous results may be accomplisheda- With reference to the drawings, 1Q desi nates the head-plate of my improved grin ing head which is herein shown with a plain, fiat, front face 11 having a relatively broad rearwardly-entending flange side face, or edge the corners ll; of the plate being nicely rounded between the flange and the of the abrasive sheetmay extend so as to prevent them from overlapping each other and the plate is also provided with a rear weirdly-extending hub 23, whereby it may be mounted upon a spindle 24 indicated in dotted lines to be rapidly rotated.

The sheet of abrasive material 15 is pref- .erably first cut into disc form and in some instances is first drawn up into cup shape asbest illustrated in Figure 6, by a separate process, the edge 16 andsurplus stock on the edge 13'being taken up in scallop form, and in order to secure the turnedback edges of this abrasive disc on the edges ortlangcs of the head-plate, I have provided a binding ring 18, the inner diameter of which is just sufficient to fit tightly over the head plate when the abrasive sheet is folded over the edge thereof tov bind the edge of the sheet onto the edge of the headplate. V

In order to facilitate the forcing of this ring orer the edge of the head-plate to bind the abrasive sheet thereon, I have provided a ring-applying tool 19 which is provided with a shouldered recessQO to receive the binding ring 18 anda shouldered recess 21 to receive and support the disc of abrasive material 15 above the ring.

The ring and the sheet being shown in position in the tool in Figure 2, and the head-plate being shown in position ready to be forced down into the ring,

Figure 8' shows the operation as having been completed and Figure 4 shows the grinding head removed from its tool with the abrasive material secured thereto by the ring 18. V

In forcing this ring 18 onto the flange or edge of the head-plate 10, it will be best seen in. Figures 7 and 8, that the surplus stock of the abrasive sheet is caused to take ascallope'd form as at 16, this surplus stock naturally being caused to extend into the spaces 14E provided for it in the periphery of the head-plate,

This binding ring 18 serves while being forced into position to draw the abrasive sheet tightly over he Working front face of the head-plate and holds it in that position while the head is rapidly rotated and the Work is pressed against it to grind the same, and after the abrasive surface has been worn from the sheet,,1t is; only necessary to drive this ring. ofiian'd remove the 7 sheet and replace i'it with afreslione.

forced tl'ierethrough but is of a size to rctain the ring which is thus driven off to release the abrasive material.

My improved grinding head is very simple and practical in its construction and is effective in its operation. and by its use I am enabled to apply a sheet or disc of abrasive material to the head and after the sheet has been used up it may be readily removed and replaced by a fresh one.

The foregoing description is directed soletowaralsthc construction illustrated, but I desire it to be understood that I reserve the privilege of resorting to all the mechanh cal changes to which the device is susceptible, the invention being defined and limited only by the terms of the appended claims;

I claim: r v m 1. In a grinding head, a head-plate having a front face and aside face, a dishshapcd nicniber formed of an abrasive sheet with a wrinkled edge, a separate ring arranged to bind the wrinkled edge of said dish-shaped member on to the side face of said head, means being provided in said side face for receiving the folds of-the wrinkled edge, and means on said head plate whereby it may be mounted to be rapidly rotated. V

2. A grinding head comprising a headplate having a front fa'ce and rearwardly extending edge having scallops thereon, and a ring for binding the edg e of an abrasive sheet on the periphery of said plate, said scallops in the'edge receivingany folds in the edge of the sheet.

3. A grinding head comprising a headplate having a peripheral edge portion an abrasivesheet stretched thereover, said pa ripher'y being recessed at' spaced intervals to receive the folds of the surplus stool-1 of the sheet when in engagement therewith, and a binding ring for drawing the sheet tightly over the face of the headplate upon-being forced into place for retaining the sheet firmly in position on'said plate.

at. A grinding head comprising ahead plate having spaced recesses. in its periphery an abrasive sheet stretched thereover and a ring binding the edge of the abrasive sheet onto the periphery of said head, said recesse's serving tore'ceive the folds of the surplus stock of the sheet,

5. A grinding head comp'rising a disc plate having a front face and a side face with a rounding connecting edge, said side face being provided with spaces or grooves arranged at intervals about its periphery, an

' abrasivefslieet stretched over said plate with thereto, the wrinkled or crimped edge of the sheet being caused by pressure of the ring to enter said grooves. r Y

6. In a grindin head, a disc late-head 5 having a side e ge with space recesses therein, a disc-shaped member of abrasive material having a corrugated e e ortion to be positioned on said head Wit t e c0rof the abrasive member to bind it to the side faoe ofsaid disc In testimony w ture.

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CHARLES H. FIELD. 

